The correct answer is C, because it is the only one with 'modal' verbs. In A, only 'will' is modal. In B, only 'make' is a verb. In D, there are months involved, which are nouns, not verbs.
The correct answer is C: all three of these verbs can be used as modal verbs with another verb, for example: She would cook; She might cook; She must cook
